The purpose of this study is to determine if the EBNA antigen can be identified in human tumors by appropriate staining using the peroxidase--immunoperoxidase (PAP) technique. Thus far we have identified the VCA antigen in cultured Burkitt's lymphoma cells which were fixed in formalin and embedded in paraffin. Because of the ubiquity and known oncogenicity of EBV, it is felt to be appropriate to determine if EBNA antigen which is indicative of the presence of EBV genome, can be identified using PAP technique in paraffin-embedded sections of a variety of human tumors.